<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>setFullYear()</title>
</head>

<body>
    <p id="demo">单击按钮显示修改后的年月日。</p>
    <button onclick="myFunction()">点我</button>
    <script>
        function myFunction() {
            var d = new Date();
            d.setFullYear(2020, 10, 3);
            var x = document.getElementById("demo");
            x.innerHTML = d;
        }
    </script>
    <p>记住 JavaScript 月数是从0至11。10是11月。</p>
</body>

</html>